As winter approaches, ensuring the stable and efficient operation of large central air conditioning systems is crucial. Proper operation and maintenance not only guarantee warmth and comfort but also are essential for the safety of the equipment through the cold season and for energy conservation and cost reduction.
I. Core Antifreeze Measures (Most Critical)
Distinguish operational states and implement corresponding strategies.
For winter-operations crew members:
Keep Power Continuous: The engine and circulating water pump must remain in a fully powered state to ensure the antifreeze protection function is always active.
Pump24/7 Operation: The preheating coil hot water pump must continuously run, and should automatically restart after power is restored even if there is a power outage, it is recommended to connect to the generator power supply system.
The Forced Start Feature: The circulating pump should have a low-temperature forced start function, which automatically activates when the water temperature falls below the set anti-freezing protection temperature.
For winter idled units:
System Drainage: When the ambient temperature falls belowAt 2°C, all积水 within the main unit, terminal, and pipeline system must be drained, all water-side heat exchangers' drain valves must be opened, and the drainage must be confirmed to be completely emptied.
Add Antifreeze: Add the appropriate proportion of antifreeze to the water system, or use compressed air to blow away excess water.
2. Preheat Coil Special Protection
Controller Settings: Outdoor Temperature BelowAt -15°C, set the minimum opening (OL) of the preheating coil controller to 20%-30% to maintain basic heat output.
Standby bypass valve: Manually open the bypass valve to supply warm water to the valve.Ensure micro-circulation of hot water with 10%-30% efficiency.
Temperature Linkage Protection: InstallationThe Pt100 temperature sensor is set to initiate at a temperature of no less than 3-5°C; the host will automatically prevent startup if the standard is not met.
3. Anti-freezing for New Air Handling Units
We've added electrically adjustable valves: Installed electric multi-blade regulating valves at the fresh air intake, linked with the fresh air unit, which automatically close during shutdown to prevent cold air intrusion.
Pre-Start Inspection: It is mandatory to confirm that the water pump is running and the water temperature is normal before starting up in winter. It is strictly prohibited to operate the fresh air handling unit if the pump is not running or the water temperature is too low.
II. Daily Operation Optimization
Proper Temperature Setting: Maintain indoor temperatures atMaintain a comfortable temperature between 18-24°C to ensure comfort and avoid energy waste; recommend using an intelligent temperature control system for automatic adjustments.
Electrical System Inspection: Regularly check for loose or corroded wiring; in low-temperature and humid environments, it is easy to accelerate the aging of electrical components, and unreliable parts should be replaced promptly.
Filter Screen Cleaning: Clean the filter screen at least once a month. In winter, with windows and doors tightly closed, indoor dust concentration increases, which can obstruct the heating efficiency.
Outdoor Unit Maintenance: Clean surface dust and debris, inspect drainage outlets to prevent freezing and blockages, ensure good ventilation and heat dissipation conditions.
Regular maintenance and upkeep
Refrigerant Check: Have a professional technician inspect refrigerant quantity and quality before winter; insufficient levels can affect heating efficiency.
Lubrication System Maintenance: Check the oil level in the compressor, replace the oil that has turned black or contains impurities, and clean the filter during both spring and autumn seasons each year.
Scale Removal in Water Systems: Scale buildup in heat exchangers of evaporators and condensers can reduce performance. Professional descaling should be conducted when a decline in refrigeration efficiency is detected.
Comprehensive Professional Inspection: Conduct a thorough system check at least once a year to promptly identify potential issues
